'Author: Dave Navarro, Don Dickinson
'Source: http://www.powerbasic.com/support/forums/Forum5/HTML/000675.html
'
'  Convert a file to MIME text (Base64 Encoded) for PB/DLL or PB/CC
'  by Dave Navarro (dave@powerbasic.com)
'
'  Modified by Don Dickinson (ddickinson@basicguru.com) to add more
'  error checking, a definable multi-part boundary, and allowing
'  for a destination file name that's different from the source name.
'
#If Not %Def(%PB_MIME_BAS)
%PB_MIME_BAS = 1
 
Function pbFileToMIME(InFile As Asciiz, OutFile As Asciiz, zOutFileName As Asciiz, zBoundary As Asciiz) As Long

   Register i        As Long
   Dim Enc           As String * 64
   Dim b             As Asciiz * 4
   Dim InBuff        As String
   Dim OutBuff       As String
   Dim InFileName    As String
   Dim iIn           As Long
   Dim iOut          As Long
   Dim iNameField    As Long
   Dim iCount        As Long

   Enc = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

   '- Open the files
   On Error Resume Next
   iIn = FreeFile
   Open InFile For Binary As #iIn
   If Err Then
      Function = %False
      Exit Function
   End If

   iOut = FreeFile
   Open OutFile For Output As #iOut
   If Err Then
      Close #iIn
      Function = %False
      Exit Function
   End If

   '- What is the name of our file.
   If Trim$(zOutFileName) = "" Then
      iNameField = ParseCount(inFile, Any ":\")
      InFileName = Parse$(inFile, Any ":\", iNameField)
   Else
      InFileName = Trim$(zOutFileName)
   End If
   Print #iOut, "Content-Type: application/octet-stream; name=" + Chr$(34) + InFileName + Chr$(34)
   Print #iOut, "Content-Transfer-Encoding: base64"
   Print #iOut, "Content-Disposition: attachment; filename=" + Chr$(34) + InFileName + Chr$(34)
   Print #iOut, ""

   While Not Eof(iIn)

      iCount = iCount + 1
      If iCount Mod 20 = 0 Then
         Dialog DoEvents
         If gAbort Then
            GoTo Abort_MimeEncode
         End If
      End If
      Get$ iIn, 57, InBuff
      OutBuff = ""
      While Len(InBuff)
         b = Left$(InBuff, 3)
         ! mov AL, b[0]
         ! shr AL, 2
         ! movzx i, AL
         OutBuff = OutBuff + Mid$(Enc, i+1, 1)
         ! mov AL, b[1]
         ! mov AH, b[0]
         ! shr AX, 4
         ! and AL, &H3F
         ! movzx i, AL
         OutBuff = OutBuff + Mid$(Enc, i+1, 1)
         If Len(InBuff) = 1 Then
            OutBuff = OutBuff + "=="
            Exit Do
         End If
         ! mov AL, b[2]
         ! mov AH, b[1]
         ! shr AX, 6
         ! and AL, &H3F
         ! movzx i, AL
         OutBuff = OutBuff + Mid$(Enc, i+1, 1)
         If Len(InBuff) = 2 Then
            OutBuff = OutBuff + "="
            Exit Do
         End If
         ! mov AL, b[2]
         ! and AL, &H3F
         ! movzx i, AL
         OutBuff = OutBuff + Mid$(Enc, i+1, 1)
         InBuff = Mid$(InBuff, 4)
         If Err Then Exit Do
      Wend
      Print #iOut, OutBuff
   Wend
   Print #iOut, ""
   Print #iOut, zBoundary

   Function = %True

Abort_MimeEncode:
   Close #iIn
   Close #iOut

End Function

#EndIf